1. Field of the Invention
The present invention is in the field of swimming pool construction, and more specifically relates to a construction which permits existing swimming pools to be provided with a spa at low cost.
2. The Prior Art
Swimming pools are customarily provided with a water pump, a filter, and a heater. The pump circulates the water from the pool, drawing the water in from the pool through a pool suction pipe. The pump then drives the water through the filter which cleanses the water, and through the heater which can be used to maintain the water at a selected comfortable temperature. After passing through the heater, the water is reintroduced into the pool through a pool return pipe.
A spa is defined as a tub or pool of water, utilizing a water pump, filter, and heater in a manner comparable to a pool. A spa differs from a pool in several characteristic ways. Normally, the water in a spa is maintained at a higher temperature than the water in a pool; temperatures up to 105 degrees F. are not uncommon. Typically, the return pipe of a spa terminates in a venturi water jet which provides a mixture of air to the hot water as the latter is returned to the spa. Normally, a spa is smaller than a swimming pool and is not used for swimming. The cost of installing or constructing a spa in the ground is comparible to the cost of a swimming pool. The number of installed swimming pools far exceeds the number of installed spas. Most pool owners do not install a separate spa, partly because of the additional cost, and partly because once the pool has been installed, there is less space available for the spa. The present invention is intended to permit the owners of swimming pools to enjoy the advantages of a spa with relatively little expense and without giving up any further yard space.